Dimensionality tuning of the electronic structure in Fe(3)Ga(4) magnetic materials

This work reports on the dimensionality effects on the magnetic behavior of Fe(3)Ga(4) compounds by means of magnetic susceptibility, electrical resistivity, and specific heat measurements. Our results show that reducing the Fe(3)Ga(4) dimensionality, via nanowire shape, intriguingly modifies its electronic structure. In particular, the bulk system exhibits two transitions, a ferromagnetic (FM) transition temperature at T(1) = 50 K and an antiferromagnetic (AFM) one at T(2) = 390 K. On the other hand, nanowires shift these transition temperatures, towards higher and lower temperature for T(1) and T(2), respectively. Moreover, the dimensionality reduction seems to also modify the microscopic nature of the T(1) transition. Instead of a FM to AFM transition, as observed in the 3D system, a transition from FM to ferrimagnetic (FERRI) or to coexistence of FM and AFM phases is found for the nanowires. Our results allowed us to propose the magnetic field-temperature phase diagram for Fe(3)Ga(4) in both bulk and nanostructured forms. The interesting microscopic tuning of the magnetic interactions induced by dimensionality in Fe(3)Ga(4) opens a new route to optimize the use of such materials in nanostructured devices.